The following extract from a communication by an officer of our army, in 1847, during the invasion of Mexico, contains some interesting facts, and corrects scientifically the measurements of the pyramid which were made by Baron Humboldt: All the mornings of this elevated region, even in the rainy season, are bright and charming; the sun rises in unclouded splendor, gilding one of the most magnificent landscapes the imagination can conceive, whilst the atmosphere is so pure and elastic that it is a positive pleasure to breathe it. On such a morning, in company with the 4th regiment of artillery, acting as infantry, and a squadron of horse, we sallied from the city through the _garita_ of Cholula, and soon found ourselves in the extensive plain skirting the base of the volcanoes of Puebla--Popocatepetl and Iztaccihuatl. Before us glittered in the morning's sun their snow-capped summits; on our right rose the Malinche, with its craggy crest partially enveloped in a wreath of mist; whilst behind us, in the far distance, towered the indistinct form of the Orizaba--that well-known landmark of the seaman, that serves to guide him in calm and in storm, hundreds of miles along the Mexican coast. The nearer landscape was as soft and picturesque as its more distant features were grand and sublime. A green meadow or prairie extended around us for some miles in every direction, dotted with villas and haciendas, and relieved by occasional patches of cultivation, and avenues and clusters of the beautiful shade willow. Herds of cattle and horses grazed as quietly on the surrounding estates as though "grim-visaged war" had long since "smoothed his wrinkled front," and our military escort, as it wound its way over the fair landscape, with glittering arms and glancing banners, seemed more like a holyday procession than a band of stern veterans so recently from the conflict, and so soon to enter it again. A ride of an hour and a quarter, which our horses, as they snuffed the morning breeze and scented the fresh grass of the meadows, seemed to enjoy as much as their riders, brought us to the base of the far-famed pyramid, which, independently of its historical recollection, and the great interest attached to it as a work of art, forms one of the most picturesque features of the landscape. At a short distance it presents the appearance of a natural mound, covered with a luxuriant growth of trees and shrubbery, and is surmounted by a simple chapel, whose belfry towers some eighty feet above the pyramid. A road winds round the pyramid from base to summit, up which we passed on horseback. This road is cut into the pyramid, in some places, six or eight feet, and here one sees the first evidence of the artificial construction of the latter. It is built of _adobes_, or sun-dried brick, interspersed with small fragments of stone--porphyry and limestone. Its dimensions, as stated by Humboldt, are: base 1,060, elevation 162 feet; but its altitude is much greater.